1. Field of the Invention
The present invention relates generally to automobiles and similar vehicles and, more specifically, to dynamic adjustment of automotive vehicle drive systems based upon road conditions.
2. Description of the Related Art
Automobiles experience a variety of road conditions that affect the handling of the automobile. For example, snow and ice impair traction. Potholes or bumps can impair steering control and cause discomfort to the occupants of the automobile.
Systems have been developed that dynamically adjust automobile driving parameters, such as suspension, braking and throttle, in response to sensed conditions. One well-known system of this type is the anti-lock braking system (ABS) common in newer automobiles. The sensed conditions may be those internal to automobile drive systems, such as the braking system in the case of ABS, or those of external parameters such as ambient air pressure. Another example of the former type of system is described in U.S. Pat. No. 5,546,308, issued to Yamamoto. In that system, the throttle is adjusted in response to the sensed state of a tire pressure sensor, a running distance sensor, an acceleration sensor, a wheel speed sensor and a brake sensor. The system responds to these sensed parameters by preventing the vehicle speed from increasing when the sensed parameters indicate that the road-holding ability of the vehicle is impaired.
The types of systems described above are often of limited effectiveness because the road conditions that caused the impairment are transient. The vehicle may have already passed the affecting section of road by the time the system can adjust the relevant drive system parameters in response. It would be desirable to provide a system that adjusts vehicle drive system parameters in response to sensed road conditions sufficiently in advance of the vehicle reaching the affecting section of road that the adjustment has the intended beneficial effect. The present invention addresses these problems and deficiencies and others in the manner described below.
The present invention relates to a method and system for producing a response to driving conditions ahead of a land vehicle such as an automobile. The driving conditions are sensed by another vehicle (the xe2x80x9cfirstxe2x80x9d vehicle) ahead of the vehicle in which the response is produced (the xe2x80x9csecondxe2x80x9d vehicle). Any suitable driving condition can be sensed, including parameters of internal vehicle mechanism dynamics such as movement of the vehicle suspension, and parameters external to the vehicle such as road features and obstacles sensed by radar, ultrasonic, optical or similar sensors. The first vehicle transmits the sensed driving condition information to the second vehicle. The response produced by the second vehicle can be any suitable electronically controlled response, including adjusting a drive system mechanism such as the vehicle""s suspension, braking, cruise control or throttle mechanisms, and including providing an indication perceptible by the driver or other occupant, such as activating a warning light or sounding a buzzer. The response can be designed to counteract or cancel the negative effects of the driving condition. For example, if the suspension of the first automobile moves in a manner that indicates one or more of its wheels have dipped into a pothole, when the second vehicle reaches the pothole it can actuate its suspension to lower the corresponding wheels to conform to the depth of the pothole and thus provide a smoother ride for the occupants.
The second vehicle can identify the first vehicle by any suitable means, such as obtaining geographic location information from global positioning satellite receivers in the vehicles and comparing them to determine whether there is a vehicle ahead that can provide the requisite driving condition information. Alternatively, if the first and second vehicles are physically or electronically linked to one another, such as in the automobile trains that have been suggested in the art, the identities of vehicles that are ahead of other vehicles can readily be identified because they are predetermined or fixed during operation of the system. Such vehicle trains have been suggested in which a number of automobiles travel at highway speeds and have automated systems that respond to radar sensors to maintain separation between the automobiles.